Sonic retorting technique for in situ minining of carbonaceous material

ABSTRACT

Conduit means which may be in the form of a plurality of pipes, or which may be in the form of a caisson, are driven into the ground to the region of a carbonaceous deposit such as oil shale or coal, the driving action being achieved by means of high level sonic energy which preferably causes resonant vibration of the conduit means. With the conduit means in the desired position, embedded in the carbonaceous material, such carbonaceous material is heated or combusted to convert it to a fluid state (liquid or gaseous, as the case may be). While such retorting is being accomplished, high level sonic energy is simultaneously applied through the conduit member to the region of the carbonaceous material, this sonic energy being concentrated in the heated region by utilizing the differing impedances presented to the sonic energy by the heated and non-heated regions. The sonic energy acts to break up the carbonaceous material and separate it from the surrounding earthen material so that the localized retorting action can be efficiently accomplished. Further, in the case of the retorting of coal, the vibratory action tends to cause the filling of voids as the retorting proceeds, which improves the quality of the end product.

United States Patent [191 Bodine [111 3,848,672 [451 Nov. 19, 1974 1 SONIC RETORTING TECHNIQUE FOR IN SITU MININING OF CARBONACEOUS MATERIAL [76] Inventor: Albert G. Bodine, 7877 Woodley Ave., Van Nuys, Calif. 91406 [22] Filed: May 21, 1973 [21] Appl. No.: 361,885

[52] US. Cl. 166/249, 166/272 [51] Int. Cl E2lb 43/24 [58] Field of Search 166/249, 272, 303

[56] References Cited UNITED STATES PATENTS 2,700,422 l/l955 Bodine 166/249 2,799,641 7/1957 Bell 166/249 UX 3,133,591 5/1964 Brandon 166/249 3,189,536 6/1965 Bodine 166/249 3,422,894 1/1969 Brandon 166/249 3,497,005 2/1970 Pelopsky et al.. 166/249 3,578,081 5/1971 Bodine 166/249 3,718,186 2/1973 Brandon 166/249 X 3,754,598 8/1973 Holloway 166/249 Primary ExaminrDavid H. Brown Attorney, Agent, or Firm-Edward A. Sokolski [5 7] ABSTRACT Conduit means which may be in the form of a plurality of pipes, or which may be in the form of a caisson, are driven into the ground to the region of a carbonaceous deposit such as oil shale or coal, the driving action being achieved by means of high level sonic energy which preferably causes resonant vibration of the conduit means. With the conduit means in the desired position, embedded in the carbonaceous material, such carbonaceous material is heated'or combusted to convert it to a fluid state (liquid or gaseous, as the case may be). While such retorting is being accomplished, high level sonic energy is simultaneously applied through the conduit member to the region of the carbonaceous material, this sonic energy being concentrated in the heated region by utilizing the differing impedances presented to the sonic energy by the heated and non-heated regions. The sonic energy acts to break up the carbonaceous material and separate it from the surrounding earthen material so that the 10- calized retorting action can be efficiently accomplished. Further, in the case of the retorting of. coal, the vibratory action tends to cause the filling of voids as the retorting proceeds, which improves the quality of the end product.

13 Claims, 9 Drawing Figures PATENTE raw 1 91974 SHEEI 2 OF 4 FIG. 2'

PAHZNIL usv 1 9 I974 SHEET 3 OF 4 PATENTEMBV 1 91914 3,848.672

' SHEET t UP 4 SONIC RETORTING TECHNIQUE FOR IN SITU MININING OF CARBONACEOUS MATERIAL This invention relates to in situ mining of solid carbonaceous material, and more particularly to such a mining technique involving the use of retorting in conjunction with sonic energy.

The conventional mining of solid carbonaceous material, such as oil shale, coal and lignite, has come under considerable scrutiny recently in view of its adverse ecological effects. Further, underground mining operations involve considerable expense and hazard which could be greatly reduced if some means could be found for mining such material from an above-ground location. Oil shale has been a known source of oil for many years. However, no efficient means have been found to date for the extraction of the oil from the kerogen deposits within the shale. Mining of the shale by conventional procedures, followed by above-ground processing involving retorting techniques, have been used to a limited degree for a great number of years. However, in view of the relatively small yield of oil for each ton of shale mined and processed, this approach has been regarded as of questionable economic feasibility. Further, this approach provides the problem of disposing of large quantities of spent shale. In order to overcome these difficulties, in situ processing of oil shale has been tried experimentally in recent years. Such in situ processes may be implemented by the sinking of a shaft into the oil shale formation and then forcing hot combustion gases through the oil shale to convert the solid organic kerogen contained therein to oil which is then drawn to the surface. In facilitating this process it has been suggested that fracturing of the shale could be accomplished by the application of hydraulic pressure, chemical explosives, or a nuclear explosive. Various such in situ retorting techniques are described in the following publications:

1. OIL SHALE AND THE ENERGY CRISIS, by G. U. Dinneen and L. Cook, US. Bureau of Mines; published by the American Society of Mechanical Engineers, 1973 (Publication No. 72-WA/Fu-3).

2. COLORADO SCHOOL OF MINES QUAR- TERLY, Vol. 59, No. 3, July 1964, pages 39-46, Retorting Oil Shale Underground; Problems and Possibilities, by B. F. Grant.

3. COLORADO SCHOOL OF MINES QUAR- TERLY, Vol. 63, No. 4, October, 1968, pages 83-108, A Look at Oil Shale Retorting Methods Based on Limited Heat Transfer Contact Surfaces, by A. L. Barnes and R. T. Ellington.

4. COLORADO SCHOOL OF MINES QUAR- TERLY, Vol. 65, No. 4, October 1970, pages 57-72, The Potential for In Situ Retorting of Oil Shale in the Piceance Creek Basin of Northwestern Colorado, by P. M. Duggan, F. S. Reynolds, and P. J. Root.

5. JOURNAL OF PETROLEUM TECHNOLOGY,

Vol. 22, 1970, pages 1520-1524, Shale Oil Recovery by In Situ Retortinga Pilot Study, by E. L. Burwell, T. E. Sterner, and H. C. Carpenter.

The experiments described in the articles listed above, particularly under Numbers 3 and 5, were indicated to be not promising in view of the fact that the fracturing technique utilized did not produce sufficient heat transfer surfaces to sustain combustion at a high enough rate for effective retorting.

The technique of the present invention overcomes the shortcoming experienced in prior art in situ retorting by engendering highly efficient transfer of the available heat energy to the carbonaceous material, this by virtue of the concentrated vibratory energy applied to locally break down such material while the retorting is being accomplished. Further, the sonic energy uniquely is confined to the region where the retorting action is being accomplished and thus is not wastefully dissipated in the surrounding area, this by virtue of the differing impedances presented to the sonic energy by the heated regions as compared with the non-heated regions. This assures concentration of the sonic energy for maximum effect in the work areas of interest.

It is therefore an object of this invention to facilitate the mining of solid carbonaceous material.

It is another object of this invention to provide sonic means for use in efficiently mining solid carbonaceous material by a retorting process.

Other objects of this invention invention will become apparent as the description proceeds in connection the accompanying drawings, of which:

FIGS. 1 and 1A are schematic drawings illustrating a first embodiment of the technique of the invention;

FIGS. 2 and 2A illustrate a second embodiment of the technique of the invention;

FIGS. 3 and 3A illustrate a third embodiment of the technique of the invention; and

FIGS. 4, 4A and 4B illustrate a fourth embodiment of the technique of the invention.

Briefly described, the technique of the invention is as follows:

Conduit means which may be in the form of a single caisson, or may comprise a pair or more of pipe members, is driven into the ground by means of sonic energy so that a portion thereof is imbedded in a region where carbonaceous material to be extracted is located. Heat energy is applied to the carbonaceous material to change such material to a fluid state (liquid or gaseous, as the case may be). This end result may be achieved by supplying hot gases to the material or by supplying an oxidant which sustains combustion of a portion thereof. In the case of oil shale, this retorting process cracks the kerogen deposits in the shale, thereby convetting such deposits to oil, while in the case of coal this causes partial combustion of the coal resulting in the generation of .coal gases. To facilitate the retorting process, while such process is occurring, high-level sonic energy is applied vthrough'the walls of the conduit means to the carbonaceous formation, this energy preferably being developed by an orbiting mass oscillator or oscillators, which may be the same oscillators .utilized in driving the conduit into-the ground.

Preferably, the sonic energy is at a frequency such as to cause resonant elastic vibration of the conduit member. The application of the sonic energy breaksupthe heated and weakened carbonaceous material and keeps it in a mobile state, tending to separate it from the surrounding material. The gaseous or liquid effluent is conducted to the surface. The sonic energy thus greatly increases the efficiency of the retorting of the solid carbonaceous material. In addition, in the case of coal or lignite retorting, the sonic energy tends to cause caving and'filling of the localized voids created with combustion of the coal, thereby assuring that the effluent retains its proper chemical composition. It is to be noted that the simultaneous application of heat energy and sonic energy to the carbonaceous material in the technique of this invention has a particular cooperative effect in that the sonic energy tends to be confined to the heated regions in view of the differing impedances between the heated and non-heated regions, the sonic energy tending to be reflected from the non-heated regions back to the heated regions which tend to have a lower reactive impedance or a greater resistive impedance. In one embodiment of the technique of the invention, the heating and/or combustion agent is supplied to the carbonaceous material through a first pipe, while the effluent, liquid or gas, is removed by means of a second pipe. In another embodiment, a single conduit in the form of a large caisson is utilized to confine the carbonaceous material, with the combustant or oxidant being fed through a pipe located within this caisson, and the effluent being drawn either directly from the inside of the caisson or through a pipe located therein.

It has been found most helpful in analyzing the technique of this invention to analogize the acoustically vibrating circuit utilized to an equivalent electrical circuit. This sort of approach to analysis is well known to those skilled in the art and is described, for example, in Chapter 2 of Sonics by Hueter and Bolt, published in 1955 by John Wiley and Sons. In making such an analogy, force F is equated with electrical voltage E, velocity of vibration u is equated with electrical current i, mechanical compliance C is equated with electrical capacitance C mass M is equated with electrical inductance L, mechanical resistance (friction) R,, is equated with electrical resistance R and mechanical impedance Z, is equated with electrical impedance Z Thus, it can be shown that if a member is elastically vibrated by means of an acoustical sinusoidal force F sinwt (w being equal to Zn times the frequency of vibration), that Z,,, R +j(a)M l/mC F sinmt/u Where wM is equal to 1/mC a resonant condition exists, and the effective mechanical impedance Z is equal to the mechanical resistance R,,,, the reactive impedance components M and l/mC cancelling each other out. Under such a resonant condition, velocity of vibration u is at a maximum, power factor is unity, and energy is more efficiently delivered to a load to which the resonant system may be coupled.

It is important to note the significance of the attainment of high acoustical Q in the resonant system being driven, to increase the efficiency of the vibration thereof and to provide a maximum amount of power. As for an equivalent electrical circuit, the Q of an acoustically vibrating circuit is defined as the sharpness of resonance thereof and is indicative of the ratio of an energy stored in each vibration cycle to the energy used in each such cycle. Q is mathematically equated to the ratio between (0M and R,,,. Thus, the effective Q of the vibrating circuit can be maximized to make for highly efficient, high-amplitude vibration by minimizing the effect of friction in the circuit and/or maximizing the effect ofv mass in such circuit.

It is also to be noted that orbiting-mass oscillators may be utilized in the implementation of the invention that automatically adjust their output frequency and phase to maintain resonance with changes in the characteristics of the load. Thus, in the face of changes in the effective mass and compliance presented by the load with changes in the conditions of the work material as it is heated and sonically excited, the system automatically in maintained in optimum resonant operation by virtue of the lock-in characteristic of Applicants unique orbiting-mass oscillators. Furthermore in this connection the oribiting mass oscillator automatically changes not only its frequency but its phase angle and therefore its power factor with changes in the resistive impedance load, to assure optimum efficiency of operation at all times.

Referring now to FIG. 1, one technique for implementing the invention is schematically illustrated. Casing member 11 has a spirally shaped anchor point 12 on one end thereof for anchoring into a carbonaceous deposit 16, which as shown may comprise oil shale having kerogen deposits 17 therein. Mounted on the top end of casing 11 is an orbiting mass oscillator 20 which may be of the type described in my U.S. Pat. No.

3,684,037. Orbiting mass oscillator 20 is driven at a speed such as to set up resonant elastic vibration of casing 11, as indicated by standing wave pattern 21. The

sonic energy is utilized to drive casing 11 into the ground in the general manner described in my aforementioned U.S. Pat. No. 3,684,037.

Spaced from casing 11 and having a similar construction thereto is casing 30 which has an anchor point 32 driven into the carbonaceous deposit 16 by means of orbiting mass oscillator 31. With casings 11 and 30 installed in place, an oxidant which may be in the form of air, or simply hot gases, is fed through inlet 35 to the interior of casing 30, this fluid passing out from the casing through apertures 38 into the surrounding carbonaceous deposits. While the oxidant or hot gases are being passed into the carbonaceous material, vibratory energy is simultaneously applied to casing 30 and from the bottom end portions of the easing into the region of the carbonaceous deposits. To further increase the sonic energy applied to the carbonaceous material, casing 11 may be resonantly vibrated at the same time as casing 30.

The sonic energy has several significant effects in implementing the cracking of the kerogen to convert it to oil. Firstly, as shown in FIG. 1A, the vibratory energy tends to fracture the material at its interface between the kerogen and the shale, due to the high shear forces concommitant with flexural vibration, and due to the difference of acoustic impedance of kerogen and rock, thus tending to facilitate the transfer of heat to the kerogen. Further, the sonic energy tends to generally break up the kerogen itself which further enhances the heating action. It is to be noted in this vein that the kerogen has a substantially different characteristic impedance from the surrounding shale, so that its particles will tend to vibrate at a different phase and stroke than those of the shale, resulting in relative movement therebetween.

It is further to be noted that the sonic energy localization becomes more pronounced as the impedance of the kerogen tends to change as it is heated, such as by softening and becoming more plastic so as to increase its resistive hysteresis impedance; and with such changes in the impedance of the load Applicants orbiting mass oscillator as noted above will tend to maintain optimum resonant vibration of the casing.

The fluid carbonaceous material passes into casing 11 through apertures 42 and is drawn to the surface and exited from the casing through outlet 47. The effluent material may in certain instances be driven to the surface by the pressure developed in the retorting operation, or in other instances may be drawn to the surface by pumping action. In some instances the agent which is injected into the carbonaceous material has a solvent extraction action which in combination with sonic energy retorting effects extraction of effluent.

It is to be noted that the sonic energy tends to be confined to the region where the retorting is being accomplished so as to be less dissipated in the surrounding cooler regions. This is by virtue of the fact that the heated regions present a more pronounced sonic energy sink and a different characteristic impedance to the sonic energy than the non-heated regions. An effective impedance match is established between the sonic vibrated caissons and the heated areas, aided by direct coupling, such that the energy tends to concentrate in these heated regions with less energy being transferred to the non-heated portions of the strata. This is particularly significant in that it assures optimum utilizationof the sonic energy to facilitate the retorting operation.

It will be seen that this method includes the step of providing sonic energy transmission along a sonic energy transmission path to the carbonaceous material simultaneously while said material is being retorted, whereby the simultaneous application of both sonic and heat energy gives a unique cooperation of mutual aid such that the sonic energy greatly improves the delivery of heat effects to the carbonaceous material and the localized heating presents a unique environment for concentrating the sonic energy which is a great aid in certain earthen solid carbonaceous formations. Referring now to said sonic energy transmission path as regards the example in FIG. 1 it should be noted that column 11 may be acoustically coupled to formation 16 simply by standing column 11 with its weight bearing into formation 16 so as to bias the formation thereby. Therefore it should be recognized that anchor means 12 is mainly to provide augmented acoustic coupling.

FIG. 1 illustrates the method whereby a longitudinal sonic wave mode is transmitted along said energy transmission path. The consequent mode in the acoustically coupled formation 16 includes a flexural pattern by virtue of the up and down component of the longitudinal mode in column 11. The flexural component in the formation acts like the leaves in a leaf spring as regards the rock layers. In other words this creates a unique cyclic shear stress in the intervening kerogen layers because of the initially solid characteristic of the kerogen. By this method it is thus possible to develop elastic shear hysteresis in carbonaceous material which makes said carbonaceous material become a very unique and effective local energy sink for sonics.

Referring now to FIGS. 2 and 2A, another embodiment of the technique of the invention is schematically illustrated. In this embodiment, a single caisson 50 is utilized to confine a volume in which the retorting process is to be performed. Caisson 50 has cutter teeth 51 and breaker teeth 52 at the bottom end thereof for cutting into the ground and stirring teeth 54 to break up material within the core formed by the caisson. Mounted along the wall of the caisson is a pipe 60 into which the oxidant or combustion gases are fed. Caisson 50 is driven into the ground such that it encompasses a carbonaceous formation 63 to be mined by means of orbiting mass oscillator 20, in the same manner as described for the previous embodiment. As for the previous embodiment, orbiting mass oscillator may be of the type described in my U.S. Pat. No. 3,684,037. It also may be desirable to use rotation of the caisson to implement the sonic driving thereof, such as described in my U.S. Pat. No. 3,211,243. As for the previous embodiment, sonic energy, preferably at a frequency such as to cause resonant vibration of the caisson, is applied from the caisson to carbonaceous formation 63 while retorting of the carbonaceous material is being accomplished by virtue of hot gases or an oxidant supplied through pipe 60. Stirring teeth 54 are particularly effective to fluidize an entrained coal body by vibrating caisson 50 during retorting so as to keep the coal body free of voids and to cause the coal to settle downward. This particular embodiment is adapted for use where the effluent is gaseous, such as in coal retorting, the gas developed in the retorting action rising freely within thecaisson and being exited through outlet 65.

It is to be noted that after the retorting has been accomplished water and/or slurry can be passed through pipe 60 into the void areas formed in the carbonaceous material to fill these areas and thus prevent subsidence. This is more important in coal retorting wherein large volumes are consumed. The injection of water, or slurry or cement into pipe 60 may be used while the caisson is being driven into the ground before retorting, this to improve the seal around the caisson as it is being installed, so as to minimize the leakage of the gases generated in the retortion process.-

Referring now to FIGS. 3 and 3A, another technique for implementing the invention is illustrated. This particular implementation of the invention involves the use of a very wide diameter caisson 70, which may be of the order of thirty feet in diameter or considerably greater. This caisson has cutting teeth 71 and is driven into the carbonaceous formation 63 by means of sonic energy supplied from orbiting mass oscillators 75 which are attached to the top edges of the caisson, this end result being achieved in the manner described in my U.S. Pat. No. 3,686,877. When caisson has been installed in place as shown in FIG. 3, pipes 76 and 77 for handling the oxidant or combustion gases and the effluent respectively, are sonically driven into place as shown in FIG. 3A by means of orbiting mass oscillator 78, which may be of the type described in my aforementioned U.S. Pat. No. 3,684,037. As for the previous embodiments, sonic energy is fed through the caisson or the pipes to the carbonaceous material while the oxidant or combustion gases are simultaneously supplied through pipe 76 to effect the retorting action. The effluent is brought to the surface through pipe 77.

Referring now to FIGS. 4, 4A and 48, still another implementation of the technique of the invention is illustrated. In this embodiment, caisson 81 is driven into the ground in the same manner as described in connection with the embodiment of FIGS. 2 and 2A, driving action being achieved by means of orbiting mass oscillator 20. This embodiment differs from the previous embodiment in that the oxidant and effluent are carried in channels 83 and 84 which are formed along the walls of caisson 81, there being a pair of septa 85 and 86 which separate these two channels. Apertures 88 are provided to afford fluid communication between each of the channels and the carbonaceous material. Otherwise the operation is as previously described.

The technique of this invention thus provides means for making in situ mining of solid carbonaceous material by retorting techniques practicable. This end result is achieved by simultaneously applying high level sonic energy to the carbonaceous formation while the retorting process is being accomplished, this tending to localize the sonic energy and its effects, enabling optimum transfer of fluids and heat energy to the carbonaceous material and facilitating the conversion of this material to fluid forrn.

While the invention has been described and illustrated in detail, it is to be clearly understood that this is intended by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of this invention being limited only by the terms of the following claims.

I claim:

1. A method for extracting from solid carbonaceous material in the earth, comprising the steps of:

installing conduit means within the earth so that a portion thereof penetrates into the carbonaceous material and a portion thereof extends above the surface of the earth,

supplying an agent through said conduit means to said carbonaceous material so as to effect retorting of such material,

while said retorting action is occurring, applying high-level sonic energythrough said conduit means to said carbonaceous material to cause fracture of said carbonaceous material and vibratory motion thereof, thereby to increase the efficiency of the retorting action, and

conducting the retorted effluent through said conduit means and out therefrom at the surface of the earth.

2. The method of claim 1 wherein said conduit means comprises a pair of casings, said casings being installed in the carbonaceous formation in spaced relationship from each other, the retorting material being fed to the carbonaceous material through one of said casings, the effluent being drawn from the carbonaceous material through the other of said casings.

3. The method of claim 1 wherein said conduit means is resonantly vibrated by means of an orbiting mass oscillator attached thereto at the surface exposed portions thereof.

4. The method of claim 1 wherein the sonic energy is used to treat the carbonaceous material as a resistive energy sink to cause heating thereof, the agent being a solvent extraction material which operates with the sonic energy to effect extraction of effluent.

5. The method of claim 1 wherein said conduit means comprises a wide diameter caisson, the retorting agent being passed through a pipe driven into the carbonaceous formation within the caisson.

6. The method of claim 5 wherein the effluent is drawn from the carbonaceous material by means of a pipe installed within the caisson.

7. The method of claim 5 wherein after the retorting has been completed, a liquid filler material is fed from the surface through said pipe to fill the void areas of the carbonaceous formation.

8. A method for converting solid carbonaceous material to fluid carbonaceous material in situ in the earth comprising the steps of:

installing column means in the earth so a portion thereof penetrates into the carbonaceous material,

feeding a gaseous material to said carbonaceous material to cause retorting thereof,

generating vibratory energy,

conducting said vibratory energy through the column means to said heated carbonaceous material at an energy level sufficient to vibrate the carbonaceous material so as to thoroughly expose it to the heat energy of the retorting, and

conducting the fluid material developed by the retorting action to the surface of the earth.

9. The method of claim 8 wherein the vibratory energy is applied to the carbonaceous material after fracture thereof to cause heating of said material I 10. The method of claim 8 wherein the sonic energy is transferred to the carbonaceous material by sonically driving said conduit means into the carbonaceous material and continuing the vibration of said conduit means during the retorting process.

11. The method of claim 10 wherein said conduit means is vibrated resonantly.

12. The method of claim 10 wherein said vibration is a longitudinal mode in said conduit means and which includes the step wherein said conduit means is acoustically coupled to said carbonaceous material so that said method includes causing a flexural component in said carbonaceous material while said carbonaceous material is in a solid state during said retorting.

13. The method of extracting oil from an oil shale body in the earth having kerogen therein, comprising the steps of:

coupling a sonic generator to said oil shale body by means of a solid member interconnecting said generator and said body,

transmitting sonic energy from said generator through said solid member to said oil shale body,

expending said sonic energy in said oil shale body as an energy sink until conversion temperature of the kerogen is reached so that shale oil is produced, and

extracting the shale oil from the earth. 

1. THE METHOD OF EXTRACTING OIL FROM AN OIL SHALE BODY IN THE EARTH HAVING KEROGEN THEREIN, COMPRISING THE STEPS OF; COUPLING A SONIC GENERATOR TO SAID OIL SHALE BODY BY MEANS OF A SOLID MEMBER INTERCONNECTING SAID GENERATOR AND SAID BODY, TRANSMITTING SONIC ENERGY FROM SAID GENERATOR THROUGH SAID SOLID MEMBER TO SAID OIL SHALE BODY, EXPENDING SAID SONIC ENERGY IN SAID OIL SHALE BODY AS AN ENERGY SINK UNTIL CONVERSION TEMPERATURE OF THE KEROGEN IS REACHED SO THAT SHALE OIL IS PRODUCED, AND EXTRACTING THE SHALE OIL FROM THE EARTH.
 2. The method of claim 1 wherein said conduit means comprises a pair of casings, said casings being installed in the carbonaceous formation in spaced relationship from each other, the retorting material being fed to the carbonaceous material through one of said casings, the effluent being drawn from the carbonaceous material through the other of said casings.
 3. The method of claim 1 wherein said conduit means is resonantly vibrated by means of an orbiting mass oscillator attached thereto at the surface exposed portions thereof.
 4. The method of claim 1 wherein the sonic energy is used to treat the carbonaceous material as a resistive energy sink to cause heating thereof, the agent being a solvent extraction material which operates with the sonic energy to effect extraction of effluent.
 5. The method of claim 1 wherein said conduit means comprises a wide diameter caisson, the retorting agent being passed through a pipe driven into the carbonaceous formation within the caisson.
 6. The method of claim 5 wherein the effluent is drawn from the carbonaceous material by means of a pipe installed within the caisson.
 7. The method of claim 5 wherein after the retorting has been completed, a liquid filler material is fed from the surface through said pipe to fill the void areas of the carbonaceous formation.
 8. A method for converting solid carbonaceous material to fluid carbonaceous material in situ in the earth comprising the steps of: installing column means in the earth so a portion thereof penetrates into the carbonaceous material, feeding a gaseous material to said carbonaceous material to cause retorting thereof, generating vibratory energy, conducting said vibratory energy through the column means to said heated carbonaceous material at an energy level sufficient to vibrate the carbonaceous material so as to thoroughly expose it to the heat energy of the retorting, and conducting the fluid material developed by the retorting action to the surface of the earth.
 9. The method of claim 8 wherein the vibratory energy is applied to the carbonaceous material after fracture thereof to cause heating of said material.
 10. The method of claim 8 wherein the sonic energy is transferred to the carbonaceous material by sonically driving said conduit means into the carbonaceous material and continuing the vibration of said conduit means during the retorting process.
 11. The method of claim 10 wherein said conduit means is vibrated resonantly.
 12. The method of claim 10 wherein said vibration is a longitudinal mode in said conduit means and which includes the step wherein said conduit means is acoustically coupled to said carbonaceous material so that said method includes causing a flexural component in said carbonaceous material while said carbonaceous material is in a solid state during said retorting.
 13. The method of extracting oil from an oil shale body in the earth having kerogen therein, comprising the steps of: coupling a sonic generator to said oil shale body by means of a solid member interconnecting said generator and said body, transmitting sonic energy from said generator through said solid member to said oil shale body, expending said sonic energy in said oil shale body as an energy sink until conversion temperature of the kerogen is reached so that shale oil is produced, and extracting the shale oil from the earth. 